What Is a Thyroid Cyst?
Thyroid cysts are thyroid nodules that contain liquid. Thyroid cysts are usually always benign, or noncancerous. In some cases, your doctor might recommend further testing or intervention, but oftentimes you’ll just need to monitor the cyst. In about fifteen percent of cases, these cysts resolve without any treatment. Thyroid cysts may be quiet large or as small as 1cm or even less than 1cm and sometimes arise very suddenly. The treatment of thyroid cysts involves radioactive iodine, anti-thyroid medications and in some cases surgery.
What Is a Cyst?
A cyst is a semi-solid, liquid or air-filled lump that develops in any part of the body. Cysts that develop in the thyroid grow in size because of sudden bleeding within them.
Types of thyroid cysts
There are two types, defined by what is inside the cyst.
- Fluid-Filled Cysts
- Complex Cysts
Fluid-Filled Cysts
These thyroid cysts are filled entirely with liquid, like pus. These are almost always benign, or noncancerous.
Complex Cysts
Complex cysts, also known as mixed echogenic nodules, have both liquid and solid components. They are more likely than fluid-filled cysts to be cancerous.
The likelihood of cancer depends on the composition of the cyst.If it is mostly liquid, the risk of cancer is less than 5%. If it is is more than 50% solid, it has about a 10% risk of being cancerous.
Causes
Doctors aren’t sure why so many people have thyroid cysts. In general, cysts can develop when ducts are blocked and fluid gets trapped in one area. Cyst growth is also related to hormone activity, and some thyroid cysts contain the hormone colloid, which is produced in the thyroid.5
Symptoms
In most cases, people with a thyroid cyst do not experience any symptoms. In fact, this is true of most kinds of thyroid nodules. However, you might experience symptoms if your cyst grows so large that it presses on the other organs in your neck. These symptoms can include:
- Difficulty breathing
- Difficulty swallowing
- Vocal changes
- Feeling of mass and pain in the neck
Diagnosis
After your doctor has detected a thyroid cyst or suspects that you may have one, he or she will likely order further testing. This will help give you both a better understanding of the cyst, so that you can choose the treatment option that is right for you.Testing will determine whether the cyst is fluid-filled or complex, and whether it’s benign or cancerous. Further testing for thyroid cysts includes:
- Ultrasound
- Biopsy
- Thyroid Scan
Ultrasound
Thyroid cysts are often detected during ultrasounds. An ultrasound can provide important information on the composition of a cyst.
Biopsy
If your doctor sees something concerning on the ultrasound, they may opt to do a fine-needle aspiration biopsy. During this procedure a very small needle is inserted through your neck into the thyroid cyst, using an ultrasound image to guide the needle. The needle removes a sample of the material of the cyst.
The cells from that sample are then analyzed under a microscope to determine whether any of the cells are cancerous. A fine-needle aspiration biopsy is most often used for cysts over 1.5 centimeters and that are complex.
Thyroid Scan
If your doctor finds that the thyroid cyst is complex, they may want to determine whether or not it’s producing thyroid hormones. A nodule that produces thyroid hormones, known as an active or toxic nodule, can cause you to experience hyperthyroidism.
References:
https://www.verywellhealth.com/thyroid-cyst-5105116
https://www.thyroidcancer.com/thyroid-cysts
